imported post
http://www.paul.net/guns/CaliforniaOpenCarry.pdf
This linkhas about everything you need information wise. You may carry in every city in CA. But it kinda takes a knowledge of the area to not end up in a 1000 foot school zone - thats a felony and yes you do have to
knowingly be in a school zone to be convicted, but just an arrest would cost you $25,000 - $50,000 to fight in court.
If you're found in a vehicle with a firearm there is a chance you could face a concealed charge. A firearm worn openly in a belt holster is not considered concealed, but with a firearm not registered with CA DOJto you the charge goes from a misdemeanor to a felony even if the statute is wrongly applied. Again money and time to defend.
Based on your latest post I see you don't fully understand the laws. 200,000 population has nothing to do with unlicensed unloaded (mags separate)open carry (Mike should really change the CA forum front page).
Read the link. It's all there. If you still have questions, based on your read, we'll have something to address.
Unless you are in a remote part of unincorporated county area and you know it is not a no discharge area the safest legal way to open carry 100% of the time (not in a 1000' school zone) is with holstered sidearm unloadedwith mags separate in an exposed mag pouch.
As for precautions, carry a recorder and have friendly witnesses. Don't act nervous while carrying. Dress conservatively. Etc... I won't try to talk you out of this as it is you decision. Have a lockable case with you for when you need to lock it up. Perhaps even register the gun with DOJ (it will remove the felony charge for concealed 1st offense but not the felony charge for a school zone). Don't speed. Use you turn signal. Smile? Carry a copy of that OC brochure.